#include <iostream>
#include <QMetaObject>
#include <QMouseEvent>
#include <QGraphicsItem>
#include <spdlog/spdlog.h>
#include <QApplication>

#include "FlowChartView.h"
#include "FlowChartScene.h"

#include "node_scene.h"
#include "node_graphics_socket.h"
#include "node_graphics_edge.h"
#include "node_graphics_node.h"
#include "node_socket.h"
#include "node_edge.h"
#include "node_node.h"
#include"node_graphics_cutLine.h"


inline static bool FCVDEBUG=false;
FlowChartView::FlowChartView(QWidget* parent ) :QGraphicsView(parent)
{
 spdlog::info("FlowChartView creat success");
	initUI();

}

FlowChartView::~FlowChartView()
{
 
 spdlog::info( "FlowChartView delete success");
}

//m_cutLine = std::make_unique<QDMGraphicsCutLine>();
void FlowChartView::init()
{
 //构造cutline
 m_cutLine = new QDMGraphicsCutLine();
 m_Scene.lock()->getFcScene()->addItem(m_cutLine);
}

/**
 * @brief 视窗的部分设置
 * @todo 
 * @param 
 * @return 
 */
void FlowChartView::initUI()
{
 //该函数用于设置渲染选项
 setRenderHints(QPainter::Antialiasing | QPainter::TextAntialiasing | QPainter::SmoothPixmapTransform);
 setViewportUpdateMode(QGraphicsView::FullViewportUpdate);
 setTransformationAnchor(QGraphicsView::AnchorUnderMouse);
 setDragMode(QGraphicsView::RubberBandDrag); 

 //进行缩放或平移操作时,变换的中心点将会是鼠标指针所在的位置,而不是视图的中心点
 setTransformationAnchor(QGraphicsView::AnchorUnderMouse);
 // enable dropping
 setAcceptDrops(true);
}


void FlowChartView::mousePressEvent(QMouseEvent* event)
{
 if (event->button() == Qt::MiddleButton) 
 {
 middleMouseButtonPress(event);
 }
 else if (event->button() == Qt::LeftButton) 
 {
 leftMouseButtonPress(event);
 }
 else if (event->button() == Qt::RightButton) 
 {
 rightMouseButtonPress(event);
 }
 else 
 {
 QGraphicsView::mousePressEvent(event);
 }
}

/**
 * @brief middleMouseButtonPress
 * 1.在用户按下鼠标中键时,先模拟释放鼠标事件,然后设置拖拽模式为手形滚动拖拽,最后再模拟按下鼠标事件,以实现启用场景的拖拽功能。
 * 2. 对于QMouseEvent和其他Qt事件对象,更常见的做法是不使用new动态分配它们,而是让它们作为局部变量在栈上分配。
 * 这样,当事件处理函数返回时,它们会自动被销毁,无需手动管理内存
 * 3.&releaseEvent是一个取地址操作,返回一个具体的内存地址
 * @todo 有点没明白为啥要先后模拟按下和释放左键
 * @todo [20240104]如果将releaseEvent和fakeEvent在堆上创建,QT是否会自行管理其生命周期呢?目前保险起见在堆上创建
 * @param param1 参数1的描述
 * @return 
 * setDragMode用户可以使用鼠标拖动视图来进行滚动
 */
void FlowChartView::middleMouseButtonPress(QMouseEvent* event)
{
 // debug printout 
 if (FCVDEBUG) { spdlog::debug("MMB DEBUG:"); } 
 
 // Create a mouse event with the button released 
 QMouseEvent releaseEvent(QEvent::MouseButtonRelease, event->localPos(), event->screenPos(), 
 Qt::LeftButton, Qt::NoButton, event->modifiers()); 
 QGraphicsView::mouseReleaseEvent(&releaseEvent); 
 
 // Change to scrollhand mode 
 setDragMode(QGraphicsView::ScrollHandDrag); 
 
 // Create a fake mouse event with the button pressed 
 QMouseEvent fakeEvent(event->type(), event->localPos(), event->screenPos(), 
 Qt::LeftButton, event->buttons() | Qt::LeftButton, event->modifiers()); 
 QGraphicsView::mousePressEvent(&fakeEvent); 

}

void FlowChartView::leftMouseButtonPress(QMouseEvent* event)
{
 auto item = getItemClicked(event);
 m_last_scene_mouse_position = mapToScene(event->pos());

 //shift多选 -------------------------------------------------------------------------------------begin
 //【240113】【class15】 shift按住实现多选 item父类是node / item能转换到edge /item为空
 if (item != nullptr)
 {
 if (dynamic_cast<QDMGraphicsNode*>(item->parentItem()) || dynamic_cast<QDMGraphicsEdge*>(item))
 {
 if (event->modifiers() == Qt::ShiftModifier)
 {
 event->ignore();
 auto fakeEvent = QMouseEvent(QEvent::MouseButtonPress, event->localPos(), event->screenPos(),
 Qt::LeftButton, event->buttons() | Qt::LeftButton,
 event->modifiers() | Qt::ControlModifier);
 QGraphicsView::mousePressEvent(&fakeEvent);
 return;
 }
 }
 }
 else
 { 
 if (event->modifiers() == Qt::ShiftModifier)
 {
 event->ignore();
 auto fakeEvent = QMouseEvent(QEvent::MouseButtonPress, event->localPos(), event->screenPos(),
 Qt::LeftButton, event->buttons() | Qt::LeftButton,
 event->modifiers() | Qt::ControlModifier);
 QGraphicsView::mousePressEvent(&fakeEvent);
 return;
 }
 }
 //shift多选 -------------------------------------------------------------------------------------end



 //socket拖线出现代码----------------------- start
 if (item != nullptr && dynamic_cast<QDMGraphicsSocket*>(item))
 {
 if (m_operationMode == OPERATIONMODE::MODE_NOOP)
 {
 m_operationMode = OPERATIONMODE::MODE_EDGE_DRAG;
 edgeDragStart(item);
 return;
 }
 }

 if (m_operationMode == OPERATIONMODE::MODE_EDGE_DRAG)
 {
 auto res = edgeDragEnd(item);
 if (res)
 {
 return;
 }
 }
 //socket拖线出现代码----------------------- end

 //cutline----------------------------------start
 if (item==nullptr)
 {
 if(event->modifiers() == Qt::ControlModifier)
 {
 // 设置操作模式为边缘检测模式
 m_operationMode = OPERATIONMODE::MODE_EDGE_CUT;
 // 创建一个假的事件,用于模拟鼠标释放事件
 auto fakeEvent = QMouseEvent(QEvent::MouseButtonRelease, event->localPos(), event->screenPos(),
 Qt::LeftButton, Qt::NoButton,event->modifiers());
 spdlog::info("control +Lmb Press");
 // 调用鼠标释放事件函数
 QGraphicsView::mouseReleaseEvent(&fakeEvent);
 QApplication::setOverrideCursor(Qt::CrossCursor);
 // 返回函数
 return;
 }
 }
 //-----------------------------------------end

 QGraphicsView::mousePressEvent(event);
 if (FCVDEBUG) { qDebug() << "LB DEBUG:"; qDebug() << item; }
}

void FlowChartView::rightMouseButtonPress(QMouseEvent* event)
{
 QGraphicsView::mousePressEvent(event);
 auto item = getItemClicked(event); //无法自动识别子类类型似乎,只能强转判断

 //240122测试用,添加node---------------------------------------
 if (event->modifiers() == Qt::ControlModifier)
 {
 auto node = std::make_shared<Node>(m_Scene, "Node Test");
 node->initUi(QList<int>{1, 2, 3}, QList<int>{1, 4});
 node->setPos(mapToScene(event->pos()));
 }
 //测试用,添加node---------------------------------------


 if (FCVDEBUG)
 {
 qDebug() << "RMB DEBUG:" << item;
 if (item != nullptr)
 {
 if (dynamic_cast<QDMGraphicsEdge*>(item))
 {
 auto gredge = dynamic_cast<QDMGraphicsEdge*>(item);
 //qDebug() << "edge is:" << gredge->getEdge() << "connect socket is:" << gredge->getEdge()->getStartSocket()
 // << "<--->" << gredge->getEdge()->getEndSocket();
 }

 if (dynamic_cast<QDMGraphicsSocket*>(item))
 {
 //qDebug() << "socket is:" << dynamic_cast<QDMGraphicsSocket*>(item)->getSocket() << "edge is:" <<
 // dynamic_cast<QDMGraphicsSocket*>(item)->getSocket()->getEdge();
 }
 qDebug() << "RB PRESS is:" << item << "pos is:" << item->pos();
 }
 else
 {
 qDebug() << "RB PRESS pos is no item";
 qDebug() << "nodes :";
 for (int i = 0; i < m_Scene.lock()->getNodes().size(); i++)
 {
 //qDebug() << m_Scene->getNodes()[i];
 }
 qDebug() << "Edges :";
 for (int i = 0; i < m_Scene.lock()->getEdges().size(); i++)
 {
 //qDebug() << m_Scene->getEdges()[i];
 }
 }
 //dynamic_cast<FlowChartScene*>(scene())->getScene()->getNodes() 逐级寻找法,有点麻烦。待定
 }
}

void FlowChartView::mouseReleaseEvent(QMouseEvent* event)
{
 if (event->button() == Qt::MiddleButton)
 {
 middleMouseButtonRelease(event);
 }
 else if (event->button() == Qt::LeftButton)
 {
 leftMouseButtonRelease(event);
 }
 else if (event->button() == Qt::RightButton)
 {
 rightMouseButtonRelease(event);
 }
 else
 {
 QGraphicsView::mouseReleaseEvent(event);
 }
}

void FlowChartView::middleMouseButtonRelease(QMouseEvent* event)
{
 if (FCVDEBUG){spdlog::debug("MMB RELEASR DEBUG:");}
 // When Middle mouse button was released
 QMouseEvent fakeEvent(event->type(), event->localPos(), event->screenPos(),
 Qt::LeftButton, event->buttons() & ~Qt::LeftButton, event->modifiers());
 QGraphicsView::mouseReleaseEvent(&fakeEvent);
 //用户可以使用鼠标在视图中创建一个矩形框来选择多个图形项
 setDragMode(QGraphicsView::RubberBandDrag);
}

void FlowChartView::leftMouseButtonRelease(QMouseEvent* event)
{
 auto item = getItemClicked(event);

 //shift 【24240113】多选 -------------------------begin
 if (item != nullptr)
 {
 if (dynamic_cast<QDMGraphicsNode*>(item->parentItem()) || dynamic_cast<QDMGraphicsEdge*>(item))
 {
 if (event->modifiers() == Qt::ShiftModifier)
 {
 event->ignore();
 auto fakeEvent = QMouseEvent(event->type(), event->localPos(), event->screenPos(),
 Qt::LeftButton, Qt::NoButton,
 event->modifiers() | Qt::ControlModifier);
 QGraphicsView::mousePressEvent(&fakeEvent);
 return;
 }
 }
 }
 else
 {
 if (event->modifiers() == Qt::ShiftModifier)
 {
 event->ignore();
 auto fakeEvent = QMouseEvent(event->type(), event->localPos(), event->screenPos(),
 Qt::LeftButton, Qt::NoButton,
 event->modifiers() | Qt::ControlModifier);
 QGraphicsView::mousePressEvent(&fakeEvent);
 return;
 }
 }
 //shift多选 --------------------------------------------------------------end


 if (m_operationMode == OPERATIONMODE::MODE_EDGE_DRAG)
 {
 //关于释放距离的判断,大于一定距离会绘制新线。
 if (distanceBetweenClickedAndReleaseIsOff(event))
 {
 auto res = edgeDragEnd(item);
 if (res)
 {
 return;
 }
 }
 }

 if (m_operationMode == OPERATIONMODE::MODE_EDGE_CUT)
 { 
 cutIntersectingEdges();
 m_cutLine->clearLinePoint();
 m_cutLine->update();
 QApplication::setOverrideCursor(Qt::ArrowCursor);
 m_operationMode = OPERATIONMODE::MODE_NOOP;
 spdlog::info("control +Lmb Release");
 return;
 }

QGraphicsView::mousePressEvent(event);
if (FCVDEBUG) { qDebug() << "lB RELEASR DEBUG:"; }
}

void FlowChartView::rightMouseButtonRelease(QMouseEvent* event)
{

 QGraphicsView::mousePressEvent(event);
 if (FCVDEBUG) { spdlog::debug("RB RELEASR DEBUG:"); }
}



/**
 * @brief 滚动事件
 * @param param1 参数1的描述
 * @return

 */
void FlowChartView::wheelEvent(QWheelEvent* event)
{
 // 如果按下了Ctrl键
 if (event->modifiers() == Qt::ControlModifier)
 {
 // calculate our zoom Factor
 // 计算出缩放因子
 qreal zoomOutFactor = 1 / m_zoomInFactor;

 // calculate zoom 取鼠标滚轮滚动的垂直方向上的滚动量
 // 计算出缩放比例
 qreal zoomFactor = 0.0;
 if (event->angleDelta().y() > 0)
 {
 // 向上滚动,放大
 zoomFactor = m_zoomInFactor;
 m_zoom += m_zoomStep;
 }
 else
 {
 // 向下滚动,缩小
 zoomFactor = zoomOutFactor;
 m_zoom -= m_zoomStep;
 }

 // 检查缩放比例是否在范围内
 bool clamped = false;
 if (m_zoom < m_zoomRange.first)
 {
 m_zoom = m_zoomRange.first;
 clamped = true;
 }
 if (m_zoom > m_zoomRange.second)
 {
 m_zoom = m_zoomRange.second;
 clamped = true;
 }

 // set scene scale
 // 设置场景缩放比例,且在允许的范围内进行缩放,同时不会进入死循环
 if (!clamped || m_zoomClamp == false)
 {
 scale(zoomFactor, zoomFactor);
 }
 }
 else
 {
 // 如果按下的不是Ctrl键,则调用父类的wheelEvent函数
 QGraphicsView::wheelEvent(event);
 }
}

void FlowChartView::mouseMoveEvent(QMouseEvent* event)
{
 if (m_operationMode == OPERATIONMODE::MODE_EDGE_DRAG)
 {
 auto pos = mapToScene(event->pos());
 m_dragEdge->getGrEdge()->setPosDestination(pos);
 m_dragEdge->getGrEdge()->update();
 }

 if (m_operationMode == OPERATIONMODE::MODE_EDGE_CUT)
 {
 auto pos = mapToScene(event->pos());
 m_cutLine->addLinePoint(pos);
 m_cutLine->update();
 }
 QGraphicsView::mouseMoveEvent(event);
}

void FlowChartView::keyPressEvent(QKeyEvent* event)
{
 if (event->key() == Qt::Key_Delete)
 {
 delteSelected();
 }
 else if(event->key() == Qt::Key_S && event->modifiers() == Qt::ControlModifier)
 {
 m_Scene.lock()->saveToFile("graph.json");
 }
 else if (event->key() == Qt::Key_L && event->modifiers() == Qt::ControlModifier)
 {
 m_Scene.lock()->loadFromFile("graph.json");
 }
 else
 {
 QGraphicsView::keyPressEvent(event);
 }
}

void FlowChartView::keyReleaseEvent(QKeyEvent* event)
{
}

//dynamic_cast<QDMGraphicsNode*>(item->parentItem())
void FlowChartView::delteSelected()
{
 for (const auto& item : m_Scene.lock()->getFcScene()->selectedItems())
 {
 if(dynamic_cast<QDMGraphicsNode*>(item)) //也删除了其端口所连线
 {
 dynamic_cast<QDMGraphicsNode*>(item)->getNode().lock()->remove();
 }

 }
 //不放在上一个循环中是为了避免多次删除
 for (const auto& item : m_Scene.lock()->getFcScene()->selectedItems())
 {
 if (item != nullptr && dynamic_cast<QDMGraphicsEdge*>(item))
 {
 dynamic_cast<QDMGraphicsEdge*>(item)->getEdge().lock()->remove();
 }
 }
}


/*
 //auto x = itemAt(pos);
 //auto cc1 = dynamic_cast<QDMGraphicsEdge*>(x); //对象能指向QDMGraphicsEdge么? 可以,向上转换 
 //auto x2 = itemAt(pos)->parentItem();
 //auto x = dynamic_cast<QDMGraphicsNode*>(itemAt(pos));
*/
QGraphicsItem* FlowChartView::getItemClicked(QMouseEvent* event)
{
 //return the object on which we're clecked/release
 QPoint pos = event->pos();
 return itemAt(pos);
}


/**
 * @brief edgeDragStart
 * 1.dynamic_cast<QDMGraphicsSocket*>(item)->getSocket() 不用检查的原因是在上级函数已经检查,此处暂没必要
 @todo 【240117】
 * A 每次调用都会创建一个新的 Edge 对象,并将其赋值给 m_dragEdge。由于 m_dragEdge 是一个 std::shared_ptr,
 所以在新的 Edge对象被赋值给 m_dragEdge之前,旧的 Edge对象会被自动删除(如果没有其他 std::shared_ptr 指向它
 在此处是合理的,每次构造一个内容不同的对象,并且在edgeDragEnd后自动删除
 B 在初始化时候构造一个,在edgeDragStart开始时候改变其初始点似乎更合理
 */
void FlowChartView::edgeDragStart(QGraphicsItem* item)
{
 auto edgeDragsocket = dynamic_cast<QDMGraphicsSocket*>(item)->getSocket();
 m_previousEdge = edgeDragsocket.lock()->getEdge().lock(); //可能返回一个有指向智能指针或空指针智能指针
 m_last_start_socket = edgeDragsocket;
 //【attention】 这里由于终点未知,所以出端口指定一个不存在的对象
 // std::weak_ptr<Socket>() 构造了一个空的 std::weak_ptr 对象,这个对象不持有任何 Socket 类型的对象的所有权或引用
 m_dragEdge = std::make_shared<Edge>(m_Scene, edgeDragsocket, std::weak_ptr<Socket>(), EDGEPATHTYPE::BezierCurve);
 m_dragEdge->initUi();

 if (FCVDEBUG)
 {
 qDebug() << "view::edgeDdragStart~Start dragging edge";
 qDebug() << "view::edgeDdragStart~assign Start socket to";
 qDebug() << "view::edgeDdragStart~dragEdge is:" ;
 }
}

bool FlowChartView::edgeDragEnd(QGraphicsItem* item)
{
 //如果有端口跳过剩余的代码并返回true 
 m_operationMode = OPERATIONMODE::MODE_NOOP;
 if (dynamic_cast<QDMGraphicsSocket*>(item))
 {
 auto socket = dynamic_cast<QDMGraphicsSocket*>(item);
 //如果起点终点一样,删除正在画的,再次为起始点设置原有edge
 if (m_last_start_socket.lock() == socket->getSocket().lock())
 {
 m_dragEdge->remove();
 if (!m_previousEdge.expired())
 {
 m_previousEdge.lock()->getStartSocket().lock()->setConnectedEdge(m_previousEdge);
 }
 return false;
 }

 if (FCVDEBUG) { qDebug() << "View :: edgeDragEnd~previous edge :"; }

 //if (FCVDEBUG) { qDebug() << "View :: edgeDragEnd~assign End socket:" << socket->getSocket(); }
 if (!m_previousEdge.expired()) //先去的edge先移除
 {
 m_previousEdge.lock()->remove();
 if (FCVDEBUG) { qDebug() << "View :: edgeDragEnd~previous edge removed"; }
 }
 m_dragEdge->setStartSocket(m_last_start_socket);
 m_dragEdge->setEndSocket(socket->getSocket());
 m_dragEdge->getStartSocket().lock()->setConnectedEdge(m_dragEdge);
 m_dragEdge->getEndSocket().lock()->setConnectedEdge(m_dragEdge);
 if (FCVDEBUG) { qDebug() << "View :: edgeDragEnd~assign start & End socket to drag edge"; }
 m_dragEdge->updatePosition();
 return true;
 }

 //【240112】没有就取消这个对象目前存在的一切
 if (FCVDEBUG) { qDebug() << "View :: edgeDragEnd~End draging edge"; }
 m_dragEdge->remove();
 //m_dragEdge = nullptr;
 //if (FCVDEBUG) { qDebug() << "View :: edgeDragEnd~about to set socket to previous edge" << m_previousEdge; }
 if (!m_previousEdge.expired())
 {
 m_previousEdge.lock()->getStartSocket().lock()->setConnectedEdge(m_previousEdge);
 }
 if (FCVDEBUG) { qDebug() << "View :: edgeDragEnd~everything done"; }


 return false;
}


/**
 * @brief 范围
 当我们距离上次 LMb 点击场景位置过于遥远时, 可以使用以下方法进行测量:
 计算两个位置之间的距离, 可以使用欧几里得距离公式来计算。
 比较当前位置与上次点击位置之间的距离是否超过了某个阈值。
 如果超过了阈值, 则认为我们与上次点击位置过于遥远, 需要进行重新定位。
 *
 * 函数计算一个阈值,即边开始阈值,并检查该距离的平方是否大于边开始阈值的平方。
 如果大于阈值,则函数返回 true,表示用户可能在画布上进行了有效的绘制操作,否则返回 false。
*@todo 还未非常清晰,后续思考整理20231209
 */

bool FlowChartView::distanceBetweenClickedAndReleaseIsOff(QMouseEvent* event)
{
 //mapToScene 函数接受一个 QPoint 类型的视口坐标作为参数,并将其转换为 QPointF 类型的场景坐标
 auto new_lmb_release_scene_pos = mapToScene(event->pos());
 auto dist_scene = new_lmb_release_scene_pos - m_last_scene_mouse_position;
 auto edge_start_threshold_sq = m_edge_start_threshold * m_edge_start_threshold;
 return (dist_scene.x() * dist_scene.x() + dist_scene.y() * dist_scene.y()) > edge_start_threshold_sq;
}

void FlowChartView::setCustomSence(std::weak_ptr<Scene> sence)
{
 m_Scene = sence;
}

void FlowChartView::cutIntersectingEdges()
{
 for (int ix = 0; ix < m_cutLine->getlinePoints().size()-1; ix++)
 {
 auto p1 = m_cutLine->getlinePoints()[ix];
 auto p2 = m_cutLine->getlinePoints()[ix + 1];

 for (const auto& edge : m_Scene.lock()->getEdges())
 {
 if (edge->getGrEdge()->intersectsWith(p1, p2))
 {
 edge->remove();
 }
 }
 }

}